SNMP Manager Programmer's Guide

Programming Examples
SNMP Manager Programmer’s Guide–134249
2-12
Managers Supporting UDP and IPC
32. The SNMP_WriteRead_() function encodes and transmits request packets and
receives and decodes response packets. This function accepts a pointer to
SNMP_HOST_INT_T, a pointer to an unencoded request packet structure, a double
pointer to the response packet structure, a pointer to a structure containing
descriptors for the encoded-packet buffer (ebuffp), and an integer describing the
kind of output messages desired. The function returns an integer describing the
outcome of its processing.
33. A second structure for holding encoded-packet buffer descriptors, myEBuff, is
declared. Descriptors in this structure are used when sending IPC packets.
34. The passed encoded-packet buffer descriptors are initialized using the Manager
Services library function EBufferReset(). This function sets a start pointer
(start_bp) and a next pointer (next_bp) to point to the beginning of the buffer, and
sets the value of remaining to the size of the buffer:
35. For UDP communication, myEBuff descriptors are set up to point past the socket
address:
36. The Manager Services library function tdm_SNMP_Encode_Packet() encodes the
request packet for transmission. This function encodes the contents of spkt into the
buffer described by myEBuff, starting at start_bp. If the third argument has been
assigned the value LOCAL_HOSTNAME, Manager Services encodes the packet for
IPC communication. If the argument has been assigned the value
REMOTE_HOSTNAME, Manager Services encodes the packet for UDP
communication. After encoding, the buffer descriptors look like this:
203
ebuffp
start_bp
next_bp
remaining
204
myEBuff
size of
sockaddr_in
remaining
start_bp
next_bp
205
myEBuff
start_bp next_bp
remaining
spkt values
size of
sockaddr_in